<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style></style>
    <script>
        var num1 =3;
        var num2 = 5;
        var result = num1 + num2;
        console.log(result);
        var str = '10';
        console.log(num1 + str);//310
        //Java是一个纯面向对象语言，而C++、JS不是纯面向语言
        //parseInt就是JS定义全局函数
        var result2 = num1 +parseInt(str);
        console.log(result2);
        alert(result2);
    </script>
</head>
<body>

</body>
</html>